| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 890500 | Personality and Individual Differences | 2014 | 4 Pages |
•The chronotypes of Polish students was determined in 2005 and again in 2011 years.•The increase in the number of “owls” and also in the Internet connection was observed.•If blue light from computer screens induces these changes is under discussion.
A comparison of the ratio of morningness/eveningness among students in the years 2005 and again 2011 in Poland revealed an increase in the number of people preferring evening activity (from 15.5% to 27.5%) and a decrease of morning type individuals. The only factor which undergone a change during this time is the number of personal computers with internet access (from 38.8% to 65.2%). We assume that the shift in the ratio of the chronotypes in both studies may have occurred due to affecting the circadian clock by the blue light emitted by computer screens.
